Three jaw chuck systems such as the CNC Lathe/Turning Center SL-45 Senes by Mori Seiki, have the capability of handling high speed lathe machining of most materials. In some operations, a work piece is mounted down through the chuck extending several feet to the left of the chuck, while the machining is done to the right of the chuck. One common operation is the facing of a work piece to a precise length to within several millimeters. The best way to accomplish this task is to affix an adjustable position stop to the left of the spinning chuck inside the rotating spindle. A numerically controlled computer (NC) lathe or manual lathe then faces the work piece at a precise distance from the stop each time. Rapid mounting and dismounting of each work piece is possible.
The only known adjustable stop for a three jaw chuck is made by the J.F. Berns Co., Inc. of Cinncinnati, Ohio. The model SS200 has a shaft clamp affixed to the outside left cabinet of the CNC lathe.
The shaft clamp holds an adjustable insertion length shaft up inside the spindle of the lathe to the desired stop position. A bearing unit is rotatably mounted at the work piece end of the adjustable length shaft. Drawbacks of this system include the extension of the adjustable insertion length shaft out into the shop floor when a long work piece is mounted. Also the stop cannot be located in the space between the jaws when the work piece has a smaller diameter than the inside diameter of the spindle. The rotating bearing unit fits the inside diameter of the spindle, and is not interchangeable. Another disadvantage is the high cost of the rotating bearing unit, and the high cost associated with its maintainability. The bearing unit is subjected to cooling liquids and metal particle penetration.
The present invention has no moving parts, and is thus more economical to use. Also the present invention can utilize the space inside the jaws for locating the stop. The present invention saves shop floor space since it is comprised of multiple extension units which are assembled to the desired length to position the stop. It never extends into the shop floor.